Quiz: A friend arrives driving a new Ferrari 612, the latest automotive masterpiece from Italy. With a top price approaching $260,000 , a modest additional sales tax would put its cost on par with the price of the average new home.

    What is the first question you ask?

    Odds are it won’t be: “Gee, what kind of gas mileage does it get?”

    Similarly, you won’t inquire about its slender trunk space, knowing that anyone with such a car is a practiced Just-In-Time shopper. He avoids the tedium of packing with his credit card.

    If interested, you could inquire discretely by visiting www.fueleconomy.gov.   There you would learn that the Ferrari gets 11 mpg in the city, 17 on the highway. It would cost about $2,584 to keep it in premium gasoline for a year, assuming that it is driven about 15,000 miles a year and premium gas costs $2.24 a gallon.

    As a practical matter the cost of gasoline is irrelevant to those who drive $260,000 cars. Indeed, the cost of gasoline matters little to those who drive $100,000 cars, $50,000 cars, and $25,000 cars.

And that may be the problem.

The United States is such a rich country, with such small taxes on gasoline, that the price of fuel is nearly trivial. Drivers may grumble at the pump, but when push comes to shove the price of gasoline ranks with too many cell phone minutes--- an inconvenience, not a disaster. Because of that, it’s difficult for Americans to sense the economy is bleeding as billions are exported to import oil.

Think of it as a ‘weak wallet signal’ problem. The indicator the works well to keep most people from buying their caviar by the pound simply doesn’t work for energy.

    The fastest way to understand this is to examine the cost of owning and operating an automobile, courtesy of the American Automobile Association . According to their figures, gas and oil for a Mercury Grand Marquis was 7.5 cents a mile in 2004. That’s less than 12 percent of the 65.4 cent a mile total cost. Indeed, insurance cost more than gas and oil. Depreciation, the largest cost of owning a car, was four times as much as the cost of gas and oil.

    And that’s for a Mercury Grand Marquis. Grandiose name notwithstanding, even the Grand Marquis LS Ultimate is sticker priced at a less than regal $30,920. That’s only $1,000 over the average sticker price. If you own a more expensive car your insurance and depreciation will cost more--- but the cost of gas and oil may be the same or lower. A Mercedes Benz E320, for instance, costs nearly twice as much as the Grand Marquis but has the same cost of gas and oil.

    Now go a step further. According to surveys,  Americans spend about 19 percent of income on transportation, mostly on automobiles. Less than 12 percent of that is spent on gas and oil. Result: for most Americans, gasoline is only about 2 percent of income. For the affluent it is much less.

        So, the lesson here is simple: the more affluent we are, the more we may need to look beyond the wallet signal.